/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *

 *  (C) 2003 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include "mpitest.h"

#include <stdio.h>

#include <stdlib.h>

#ifdef HAVE_STRINGS_H

#include <strings.h>

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#endif

/*

static char MTEST_Descrip[] = "A simple test of Comm_spawn";

*/

int main(int argc, char *argv[])

{

    int errs = 0, err;

    int rank, size, rsize, i;

    int np = 2;

    int errcodes[2];

    MPI_Comm parentcomm, intercomm;

    MPI_Status status;

    int can_spawn;

    MTest_Init(&argc, &argv);

    errs += MTestSpawnPossible(&can_spawn);

    if (can_spawn) {

        MPI_Comm_get_parent(&parentcomm);

        if (parentcomm == MPI_COMM_NULL) {

            /* Create 2 more processes */

            MPI_Comm_spawn((char *) "./spawn1", MPI_ARGV_NULL, np,

                           MPI_INFO_NULL, 0, MPI_COMM_WORLD, &intercomm, errcodes);

        }

        else

            intercomm = parentcomm;

        /* We now have a valid intercomm */

        MPI_Comm_remote_size(intercomm, &rsize);

        MPI_Comm_size(intercomm, &size);

        MPI_Comm_rank(intercomm, &rank;;

        if (parentcomm == MPI_COMM_NULL) {

            /* Master */

            if (rsize != np) {

                errs++;

                printf("Did not create %d processes (got %d)\n", np, rsize);

            }

            if (rank == 0) {

                for (i = 0; i < rsize; i++) {

                    MPI_Send(&i, 1, MPI_INT, i, 0, intercomm);

                }

                /* We could use intercomm reduce to get the errors from the

                 * children, but we'll use a simpler loop to make sure that

                 * we get valid data */

                for (i = 0; i < rsize; i++) {

                    MPI_Recv(&err, 1, MPI_INT, i, 1, intercomm, MPI_STATUS_IGNORE);

                    errs += err;

                }

            }

        }

        else {

            /* Child */

            char cname[MPI_MAX_OBJECT_NAME];

            int rlen;

            if (size != np) {

                errs++;

                printf("(Child) Did not create %d processes (got %d)\n", np, size);

            }

            /* Check the name of the parent */

            cname[0] = 0;

            MPI_Comm_get_name(intercomm, cname, &rlen);

            /* MPI-2 section 8.4 requires that the parent have this

             * default name */

            if (strcmp(cname, "MPI_COMM_PARENT") != 0) {

                errs++;

                printf("Name of parent is not correct\n");

                if (rlen > 0 && cname[0]) {

                    printf(" Got %s but expected MPI_COMM_PARENT\n", cname);

                }

                else {

                    printf(" Expected MPI_COMM_PARENT but no name set\n");

                }

            }

            MPI_Recv(&i, 1, MPI_INT, 0, 0, intercomm, &status);

            if (i != rank) {

                errs++;

                printf("Unexpected rank on child %d (%d)\n", rank, i);

            }

            /* Send the errs back to the master process */

            MPI_Ssend(&errs, 1, MPI_INT, 0, 1, intercomm);

        }

        /* It isn't necessary to free the intercomm, but it should not hurt */

        /* Using Comm_disconnect instead of free should provide a stronger

         * test, as a high-quality MPI implementation will be able to

         * recover some resources that it should hold on to in the case

         * of MPI_Comm_free */

        /*     MPI_Comm_free(&intercomm); */

        MPI_Comm_disconnect(&intercomm);

        /* Note that the MTest_Finalize get errs only over COMM_WORLD */

        /* Note also that both the parent and child will generate "No Errors"

         * if both call MTest_Finalize */

        if (parentcomm == MPI_COMM_NULL) {

            MTest_Finalize(errs);

        }

    }

    else {

        MTest_Finalize(errs);

    }

    MPI_Finalize();

    return 0;

}